This is just a bit of nonsensical fun, really. Here is the place to suggest dares for people to include in their novels. They can be anything from a purple tree to a character who speaks backwards or breaking the fourth wall.

Also, you can make stages of dares, getting more extreme. The Nano site is filled with stuff like this, so atke a look around - if you're feeling low on inspiration, have a go. Post some of your favourite here, or make up your own to share.